Valve seat grinder



uy 2, M350 o. DUTRO ET AL 2,006,530

VALVE SEAT GRINDER Filed April 2, l95 4 ATTORNEYS.

Patented July 2, 1935 Claude O. Dutro an d Nellie M. Jennings,

Raytown, Mo.

Application April 2, 1934, Serial No. 718,601

6 Claims.

This invention relates to grinders for the valve seats of internal combustion engines and the primary object is to provide such a tool wherein is embodied unique Ystructure whereby the grinding operation may be accomplished without complete disassembling where the valve seats are located in positions inaccessible to grinders not especially Vadapted for the work.

One of the important aims of the present invention is to provide a valve seat grinder having a'body that may be longitudinally arched to permit applying power to an abrading head that is in engagement with a valve seat disposed in a position where a straight body could not be used.

A further object of the invention is the provision of a valve seat .grinder that is made of but a few number of parts; is exceptionally strong; and has, as one of its structural features, a pilot pin engaging bearing that extends into the spring body of the grinder a suicient distance to relieve the effect of short leverage whereby objectionable side pressure on the abrading head is eliminated during the grinding operation.

Since' the specific relation between the component parts of a valve seat grinder embodying this .invention comprises some of the most important aims and objects thereof, itrwill be nec- !essa'y to refer to the following specification to obtain an understanding of the important structural details which are clearly illustrated in the accompanying drawing. Y In this drawing:

Figure 1 is a side elevation of a complete valve seat grinder in operative position and embodying this invention.

Fig. 2 is an enlarged side elevation of the valve seat grinder element embodying this invention and entirely removed from the source of power and work.

Fig. 3 is a longitudinal central section through the unit shown in Fig. 2.

Fig. 4 is a top plan View of the unit, and

Fig. 5 is a cross section taken on line V-V of Fig. 2. Y

An understanding of this art teaches that a certain number of the valve seats 8 formed in the engine blocks l0 of internal combustion motors are located in inaccessible positions such as beneath hood braces, cowls and other parts of the motor car. It therefore becomes necessary that the valve seat grinder be formed so that parts thereof might be flexed to reach the work. Ordinarily, and as is the case in the present invention, a motor I2 is employed to supply the motivating power to the abrading head I4 of the grinder. This motor I2 is equipped with a chuck I6 that releasably engages the drive connection I8 of the tool which, in turn, is detachably secured toa coupling member 20 that is rigidly attached to one end of a spring body 22, as illustrated in Fig. 3.

Coupling member 2|] in this particular instance, has an opening 24 formed therethrough and internal threads-engage threads. 26 formed on the drive connection I8. In securing coupling member 20 to one end of spring body 22, welding, brazing, soldering, or similarY methods of lattachment should be employed to assure rigid attachment. Y

'I'he abrading head I4 may be of any suitable form, but it is preferred thatthisr head Abe removably aiixed so 'that its abrading surfaces may be renewed. In the form of head illustrated, several abrading Ielements 28 are `shown and the abrading head proper is made of metal having anA opening formed therethrough that is internally scre'wthreaded as at 30 to engage screwthreads 32 iormedfon neck 34 of thespe# cially formed bearing member shown in Vdetail in Fig.3." This bearing member has a longitudinally extending pa'ssagelili formed therethrough to receive pilot pin 38 and 'the 'plane of" attachment betweenspring body 22` and this bearing member is closerrto one-end thereof; than the other. As shown;'screwtlre'a'ds'v 32 are formed between this planeetr connection and' the proximal end. The means for engaging this end of spring body 22 is an annular ange 36 which should be rigidly affixed to spring body 22 to prevent any relative movement. That portion of the bearing between ilange 36 and the innermost end is frusto-conical and this portion 40 is appreciably smaller in diameter than the inside diameter of spring body 22.

When the valve seat grinder is in operative position pilot pin 38 extends through passage 36 and because the coils of helical spring `22 are slightly spaced apart, longitudinal arching off body 22 becomes relatively easy. During this arching, power is transmitted from motor I2 to abrading head I4 and the resiliency established between the source of power and the surface being ground by spring 22 allows variation in holding pressure without altering the pressure at the abrading head. When the tool is lifted from the grinding position, the release is not sudden and an exceptionally smooth surface is created because as the abrading head I4 is rapidly rotated, the lifting of the tool becomes gradual.

The attachment between body 22 and the bear- 2 ing member is a considerable distance below the upper end of pilot pin 38 and. as a result, side pressure is minimized because of the distance between the plane of attachment and the upper end of pin 38. Y The resiliency of spring body 22 also enters into consideration and power from motor I2 is transmitted to the abrading head I4 .only after taking up the resiliency inherent in this spring body 22. It has been foundthat using a spring oi this character and emplfng a pilot pin bearing which projects into the said spring produces an exceptional grinder and combining the same with a pilot pin and motor creates a valve seat grinder having unusual characteristics producing highly desirable work. Y

Havingvthus described the invention, what is claimed as new and desired to be secured by Letters Patent is: I i

1. A valve seat grinder comprising a.Y helical spring body; a coupling member carried by theV body at one` end thereof; a head having abrading elements carried by the other end of said spring body; and a bearing establishing connection between the body and head havinga. ,portion extending into the body along the normal axis of the helical spring forming the same andinv spaced Vspring body; a coupling member byV the body` at one'end thereof; a head havingabrading elements carriedby the other end of saidA spring body; and abearing establishing connection-between the body and head havinga mism-conical portion extending into the body along the normal axisof the helical'spring forming the same Vand a neck extending outwardly from the end ,oft the spring body along itsextendedrnomml axis, Vsaid truste-conical portion being wpreclablyvgreater inlengththan-saidneck. 1f Y l 4. A valve seat grinder for engine blocks having apilot `pin positioned to be clreumscribed bythe valve seat, comprising a helical' meansfor aixing a. driving to one end of said spring body; an abraiding head carried by the other end of said body; and a bearing.

member establishing connection between the' spring body and abrading head having a passageV formed therethrough on the axis of the said body, said pilot pin extending through said passage when the grinder is in operative position to grind the valve seat, the major portion of the said passage being Within and circumscribed by the said helical spring body. v

5. A valve seat grinder for engine blocks having a pilot pin positioned to be circumscribed by the valve seat, comprisinga helical spring body; mi'aans for afiixing a driving connection to one end of said spring body; an abraiding headfcarried by the other end of said body;

'and' fa bearing member establishing connecition'between the spring body and abrading head having a passage formed therein on ythe normal axis of the said body, said pilot pink extending into said passage when the4 grinder is in operative position` to grind the valve seat, the plane of connection between body member being a; substantial distanceV below the longitudinal center of the said passage and that portion of the bearing member within said spring being relatively` small in diameter to permit arching the body out oi' normalstraight form.

6. A valve seat grinder for engine blockshaving a pilot pin positioned t'o be circumscribed by the valve seat, comprising a helical spring body; means for aiiixing a driving connection to one end of -said spring body; an abrading head car`r Y lried by the other end of said body; and abearlng member establishing connection between the other end of said spring body'and the abrading head comprising a. longitudinally hollow body, an external annular flange. integral with the body adjacent one end of the body and in direct engagement with the end of said spring body and means formed --by the bearing y.member between the saidv flange and the proximal end thereof for engaging the said abrading head.

vthe portion of said bearing member between the flange and other end oftheformer being relatively small in diameter to allow-longitudinal arching of the spring boda/.when the pilot pin is jour'- nalied in the hollow lbody without jectionable side pressure to the said abrading head during the grinding operation. s

1 CLAUDE O. DU'I'RO.

NELIIE M. JENNINGS. 

